After winning his second gold medal of the 2015 IAAF World Championships in Beijing, Usain Bolt opened the door on the possibility of his retirement after the 2016 Summer Olympics in his post-race press conference.

"After Rio, my sponsors said let's go one more year,” Bolt told reporters in Beijing. “My coach said ‘Listen to me. If you're not going to be serious about going to the world championships in London, then you shouldn't do it.’ So it's all about how I feel after Rio and if I feel I can really put my body through one more season. If I’m going to be focused and I’m going to be determined. That will determine if I compete after Rio. So we’ll see where it goes.”

Bolt's contract with Puma, reportedly worth $10 million, runs through the 2017 IAAF World Championships in London. Upon his retirement, Bolt will be paid $4 million per year as a Puma ambassador.

Bolt will turn 30 on the day of the 2016 Summer Olympics' closing ceremony.

Here is a history of Usain Bolt retirement rumors since the 2012 Summer Olympics:

Sept. 2013 - “So far, [it] is after the Olympics in Rio,” Bolt said of his retirement plans. “I think if I am in great shape, I'll go there and do what I have to do. I think it will be a good time to retire, on top.”

Aug. 2014 - After winning gold in the 4x100-meter run, Bolt says he will retire after Rio. He toldThe Telegraph. “I spoke to Michael Johnson, who said he retired because there was nothing else left to accomplish. I’m happy to have achieved everything that I have, but when you don’t have anything left then you might as well retire. I would leave the sport to all the young kids coming through, because I hate losing.”

Feb. 2015 - Bolt says he will retire after the 2017 IAAF World Championships. He tells NBC Sports' Nick Zaccardi that if he does not think that he could retire if he happened to lose his final race at the world championships.

April 2015 - Bolt says he hopes to lower his 200-meter world record before retiring. His final Olympics and preparations for the 2017 season will be featured in an upcoming documentary.

June 2015 - Bolt toys with the idea of having more fun in his final year of competition and possibly following the example set by 400-meter world record holder Michael Johnson, who ran relays in his final season. “I've told (agent Ricky Simms) when the last season comes, we should just do crazy things and ask for like random things and be a diva,” Bolt told ESPN. “I think in 2017, we should change it up and ask for blue Skittles when we get to meets. Evian water only. Stuff like that.”

July 2015 - Bolt tells Inside Athletics' Ato Boldon that he has considered running the 100-meters at the 2017 IAAF World Championships and train for the 4x400-meter run. “It would be nice to run the 4x4 at a championship.”

Aug. 2015 - Bolt says the possibility of retiring after next summer's Rio Olympics is “50-50” and the sport is “not as fun as it used to be.”